1. Field
The disclosed aspects relate generally to communications between and/or within devices and specifically to methods and systems for improving a radio frequency (RF) discovery process associated with peer mode passive communication connection establishment.
2. Background
Advances in technology have resulted in smaller and more powerful personal computing devices. For example, there currently exist a variety of portable personal computing devices, including wireless computing devices, such as portable wireless telephones, personal digital assistants (PDAs) and paging devices that are each small, lightweight, and can be easily carried by users. More specifically, the portable wireless telephones, for example, further include cellular telephones that communicate voice and data packets over wireless networks. Many such cellular telephones are being manufactured with relatively large increases in computing capabilities, and as such, are becoming tantamount to small personal computers and hand-held PDAs. Further, such devices are being manufactured to enable communications using a variety of frequencies and applicable coverage areas, such as cellular communications, wireless local area network (WLAN) communications, near field communication (NFC), etc.
NFC enabled devices may operation in a polling mode and/or a listening mode. When operating in a polling mode a device generates an RF carrier that can supply energy to a remote device. The polling device may modulate the RF carrier appropriately in order to begin communication with the remote device. When operating in a listening mode a device does not generate any RF carrier, but when exposed to a carrier from a remote device, the device may harvest energy from the field, and decode the incoming modulation to begin communication. Once communications have been established, the peer devices remain fixed in their respective polling or listening modes. Such communications are referred to as passive communications (e.g., ISO 18092 Passive Communication). At present, a NFC device is only operable to communication using ISO 18092 Passive Communication. As such, once a link is established, the role as polling or listening device is fixed for the communication duration. For peer mode operation, this communication duration may last longer than a brief “touch to do” operation such as transit access or pay by mobile.
Because of the polling device generates the RF carrier that supplies energy to the remote peer device, and because the roles of the polling device and listening device are fixed for the duration of peer communications, the power usage requirements on the polling device may be disproportionally greater than power usage requirements on the listening device (e.g., the polling device may use many tens of milliamps just to drive the antenna). During RF discovery a device may generally alternate periodically between polling and listening modes. In other words, currently it is a matter of chance which peer device will end up being the polling device once communication is established. As such, a device that is operating in a low available power range may still be responsible for power requirements associated with being a polling device in peer communications, irrespective of available power levels associated with the peer device. Thus, improved apparatus and methods for providing peer mode passive communications that take into account a power level available to operate a NFC device may be desired.